package com.mrtaohuan.servlet.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import com.google.inject.Singleton;

@Singleton
public class AuthenticationFilter implements Filter {

	@Override
	public void destroy() {
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		final HttpServletRequest httpServletRequest = (HttpServletRequest) request;
		if (httpServletRequest.getSession().getAttribute("user") == null) {
			request.getRequestDispatcher("/login").forward(request, response);
			return;
		}
		chain.doFilter(request, response);
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {
	}

}
